Usb Host Port


I've been pondering doing something like this myself, but I don't entirely trust my soldering skills on things that fiddly.

Does anyone know what the purpose of the two caps on the +5v line is? I can understand having one maybe for voltage smoothing, but why two?
And I notice this doesn't have the filtering bits like the BOB schematics on the wiki, is the filtering not that important then? Would it help much to add it?

(wishing I hadn't quit the electronics degree now :D)
 
oqnet posted on Jul 26 2006 at 10:52 AM said:
I haven't opened the gp2x to see if theres room but it might be worth putting the jack a inch or so away from the headphones and just wiring the tvout to that and leaving the headphones alone.
Ahem, if you follow the links above you will see how much room there is. I also posted the idea of a second jack a couple posts back.

jmetal88 posted on Jul 26 2006 at 11:28 AM said:
I think with the way I've got it figured out, it would work with headphones and A/V, but I'd need a custom A/V cable, as the pre-made ones (according to pinouts.ru) all have the ground in the wrong half of the jack to work with standard headphones as well. I'm hoping that grounding the video won't have any adverse effects, but I don't see why it should since the video signal should be turned off anyway whenever the TV-Out is disabled.
I would just re-wire the jack (not the plug) so that it came out all right, IE cut both of the last two traces and then use two jumpers to re-connect.

Ideally we need to get the Conexant encoder initialized in Video mode, that way we don't need to "hack" the S-Video with a capacitor to put the chroma channel back in. I don't know how, but I am sure since the source is out there we can just init. the conexant with our own script fairly easily.

deathterrapin posted on Jul 26 2006 at 11:52 AM said:
I've been pondering doing something like this myself, but I don't entirely trust my soldering skills on things that fiddly.

Does anyone know what the purpose of the two caps on the +5v line is? I can understand having one maybe for voltage smoothing, but why two?
And I notice this doesn't have the filtering bits like the BOB schematics on the wiki, is the filtering not that important then? Would it help much to add it?

(wishing I hadn't quit the electronics degree now :D)
I don't know where he is going with that either, but I would for sure use a real termination chip if I were to do this mod.

http://www1.mouser.com/index.cfm?handler=d...roductid=960951

This is a surface-mount 6 leg IC for 19.5 cents, only available from mouser.com in packs of 4,000 though, but I am sure you can source it elsewhere for less than $2. At the bare minimum build the circuit in the wiki for Host termination, I did out of 4 resistors and 2 capacitors and it works great, and is definately small enough to fit in there :).

Quick thought, would this be a problem with Radek's 8-way to 4-way stick mod? I also am curious whether his mod couldn't be done entirely in the Linux Driver and free up 4 input buttons for other uses, and of course negate the need for the hardware?

Once again it is a mystery to me why GPH didn't make this standard, it couldn't possibly have been that difficult. (it IS however smart in a business sense, they sell 2X the PSUs and a $50 lame-ass BoB this way)


Back again, I hope that somebody can put this (USB hack) on a bit of printed circuit board with surface-mount devices, to filter the power and USB, and sell it. I am just assuming here, but it may be of interest to Evildragon to sell pre-modded ones like this at his shop, and/or sell the service.

If it catches on as a popular mod then maybe GPH can design it in for the Mark 3. About time darnit.
 
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nubie posted on Jul 26 2006 at 03:38 PM said:
jmetal88 posted on Jul 26 2006 at 11:28 AM said:
I think with the way I've got it figured out, it would work with headphones and A/V, but I'd need a custom A/V cable, as the pre-made ones (according to pinouts.ru) all have the ground in the wrong half of the jack to work with standard headphones as well. I'm hoping that grounding the video won't have any adverse effects, but I don't see why it should since the video signal should be turned off anyway whenever the TV-Out is disabled.
I would just re-wire the jack (not the plug) so that it came out all right, IE cut both of the last two traces and then use two jumpers to re-connect.

I think you have missed my point at least twice now. I want a jack that I can get Video and Stereo out from. I also want to be able to plug headphones into this jack with no problems, without using an adapter. The only trace I would need to cut would be Sense, and I would rewire that to the front of the jack, using the method I described earlier. I would then add the video to that trace, and wire my video adapter cable accordingly. That way, I would be able to use headphones and A/V out without any problems.
 
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jmetal88 posted on Jul 26 2006 at 01:47 PM said:
I think you have missed my point at least twice now. I want a jack that I can get Video and Stereo out from. I also want to be able to plug headphones into this jack with no problems, without using an adapter. The only trace I would need to cut would be Sense, and I would rewire that to the front of the jack, using the method I described earlier. I would then add the video to that trace, and wire my video adapter cable accordingly. That way, I would be able to use headphones and A/V out without any problems.
I never intended my idea to not work with headphones (PS the iPod will do video and it doesn't upset the use of the headphones the way they do it).

I think you are a bit confused, one of the two conductors (the original ground, now split), is ground, the other is video.

Wire video to the correct one, then wire ground to the correct one.

When you plug in a normal headphones the ground is as big as both conductors, so the headphones will be grounded.

jmetal88 posted on Jul 26 2006 at 01:59 PM said:
Hmm...


Here's a perfect candidate for wiring up, also available from mouser.com:


http://www.mouser.com/catalog/specsheets/KC-300140.pdf
Please take a look at the wiring diagram on the very PDF you show here, you will see yellow (video) is connected directly to the one just next to the ground.

Just wire your socket so that L/R and ground work properly, then put the video in the video terminal.

Then not only will regular camcorder (and portable media player) A/V cables work, but headphones will work too.


To re-iterate, cut the last two traces if need be, then proper A/V and headphones will work.

Wire the proper one to ground and the proper one to Video. (why do it wrong when you can just do it right the first time?)
 
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nubie posted on Jul 26 2006 at 04:40 PM said:
jmetal88 posted on Jul 26 2006 at 01:47 PM said:
I think you have missed my point at least twice now. I want a jack that I can get Video and Stereo out from. I also want to be able to plug headphones into this jack with no problems, without using an adapter. The only trace I would need to cut would be Sense, and I would rewire that to the front of the jack, using the method I described earlier. I would then add the video to that trace, and wire my video adapter cable accordingly. That way, I would be able to use headphones and A/V out without any problems.
I never intended my idea to not work with headphones (PS the iPod will do video and it doesn't upset the use of the headphones the way they do it).

I think you are a bit confused, one of the two conductors (the original ground, now split), is ground, the other is video.

Wire video to the correct one, then wire ground to the correct one.

When you plug in a normal headphones the ground is as big as both conductors, so the headphones will be grounded.

jmetal88 posted on Jul 26 2006 at 01:59 PM said:
Hmm...


Here's a perfect candidate for wiring up, also available from mouser.com:


http://www.mouser.com/catalog/specsheets/KC-300140.pdf
Please take a look at the wiring diagram on the very PDF you show here, you will see yellow (video) is connected directly to the one just next to the ground.

Just wire your socket so that L/R and ground work properly, then put the video in the video terminal.

Then not only will regular camcorder (and portable media player) A/V cables work, but headphones will work too.


To re-iterate, cut the last two traces if need be, then proper A/V and headphones will work.

Wire the proper one to ground and the proper one to Video. (why do it wrong when you can just do it right the first time?)

So... You're telling me all the pinouts on this page:

http://pinouts.ru/Home/av_jack_pinout.shtml

are wrong?


The only way I can possibly see this working is if the tip is the left channel, the first ring is the right channel, the second ring is the video, and the sleeve is ground. There are no pinouts I have found that match that, aside from the PDF I posted, and that has no jacks on it, and the left and right wires are reversed as well.

Can you please elaborate more on what you're talking about, as I obviously do not understand? You should only need to cut one trace, the sense trace, and it should work.
 
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jmetal88 posted on Jul 26 2006 at 03:15 PM said:
So... You're telling me all the pinouts on this page:

http://pinouts.ru/Home/av_jack_pinout.shtml

are wrong?
We really need to start a different thread, maybe a mod could re-name and move our posts, or we could start the new thread and get a merge.

Here is coming from the web-page you show:
Trying to connect different camcorders and a/v equipment can become confusing when different manufacturers produce identical cables with different pinout connections.
This information should be correct, but may be not.

I would check a standard cable from Radio Shack or something and see what is up.

I guess I was expecting some sort of intelligent or rational thought would have gone into the design of the cables, or I just have one here wired the way I say (see above quote), from a different company.

I suppose if this pinout is right for half of them then you will have to wire your own up. I didn't know everyone could be so dumb, what was the thought process when making these cables?
 
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nubie posted on Jul 26 2006 at 05:33 PM said:
jmetal88 posted on Jul 26 2006 at 03:15 PM said:
So... You're telling me all the pinouts on this page:

http://pinouts.ru/Home/av_jack_pinout.shtml

are wrong?
We really need to start a different thread, maybe a mod could re-name and move our posts, or we could start the new thread and get a merge.

Here is coming from the web-page you show:
Trying to connect different camcorders and a/v equipment can become confusing when different manufacturers produce identical cables with different pinout connections.
This information should be correct, but may be not.

I would check a standard cable from Radio Shack or something and see what is up.

I guess I was expecting some sort of intelligent or rational thought would have gone into the design of the cables, or I just have one here wired the way I say (see above quote), from a different company.

I suppose if this pinout is right for half of them then you will have to wire your own up. I didn't know everyone could be so dumb, what was the thought process when making these cables?

Yeah, I'll check one from Radio Shack if they have them. I think I said before, their part selections kind of suck lately. Especially here in town.

EDIT:
Pfft. I just checked their web site and their camcorder cables are listed as 'web only'. I dunno any other places around here that would have them. I may just order that cable from Mouser (much cheaper) and wire it up myself in the most logical configuration. Which reminds me, I should probably use my multimeter to check if the pin that I think is ground on the headphone port really is.
 
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anyone know how to get the 5v on a mk 1 gp2x? because mine gp2x have none C158 just a C168 and this one delivers just about 0,9V ... :-/
 
fheusel posted on Jul 26 2006 at 03:41 PM said:
anyone know how to get the 5v on a mk 1 gp2x? because mine gp2x have none C158 just a C168 and this one delivers just about 0,9V ... :-/
Try finding a data sheet on the DC-DC convertor chip he mentioned and tracing out from the chip to a good solder point.

It is possible that the MK1 doesn't deliver 5 volts.
 
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Ah, I just found a much cheaper alternative that has the connectors on it already:

http://cgi.ebay.com/6-Camcorder-to-TV-Mini...1QQcmdZViewItem

I would just hope that its plug is small enough to fit in the GP2X heaphone socket, with its being recessed and all.

Also, I would hope that it is wired in a logical fashion, but since it is said to work with Sony, it may not be (if pinouts.ru is correct, which has still not been proven).

EDIT:

Ah, I just found a site listing better pinouts. Turns out, you could use an Archos, Zen Vision:M, or Apple iBook A/V cable without modification. So it looks like the camcorder thing is a no-go already, I'll have to look for one of those three.

EDIT 2: Dang, those things are at least $20.
 
fheusel posted on Jul 26 2006 at 06:13 PM said:
i found a datasheet of the DC-DC convertor --> http://pdfserv.maxim-ic.com/en/ds/MAX1566-MAX1567.pdf
if i read right there should be 5v on pin 25? i got just 3,8V..
It would be nice if someone could help me to find a way to get 5v on the MK 1 gp2x-board.

thanks
fheusel

Well, you could always test random solderable spots with a multimeter until you come up with 5v. If I has a PSU, I would do it, but I don't.
 
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fheusel posted on Jul 26 2006 at 04:13 PM said:
i found a datasheet of the DC-DC convertor --> http://pdfserv.maxim-ic.com/en/ds/MAX1566-MAX1567.pdf
if i read right there should be 5v on pin 25? i got just 3,8V..
It would be nice if someone could help me to find a way to get 5v on the MK 1 gp2x-board.

thanks
fheusel
Is that the actual power chip of the MK1? If so then it is possible that the voltage is set differently.

I can't decipher that document for some reason (I am a bit dizzy, I am sick right now with the flu), but it seems like the voltage is set by some means, maybe that is different from the MK2.

If I absolutely needed the internal 5volts, I would sell the MK1 on ebay and buy a Play-Asia.com (AKA the cheapest) Mark 2 as your best bet at getting this mod working with a minimum of hassle.
 
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jmetal88 posted on Jul 26 2006 at 04:48 PM said:
Ah at I just found a much cheaper alternative that has the connectors on it already:

http://cgi.ebay.com/6-Camcorder-to-TV-Mini...1QQcmdZViewItem

I would just hope that its plug is small enough to fit in the GP2X heaphone socket, with its being recessed and all.

Also, I would hope that it is wired in a logical fashion, but since it is said to work with Sony, it may not be (if pinouts.ru is correct, which has still not been proven).

EDIT:

Ah, I just found a site listing better pinouts. Turns out, you could use an Archos, Zen Vision:M, or Apple iBook A/V cable without modification. So it looks like the camcorder thing is a no-go already, I'll have to look for one of those three.

EDIT 2: Dang, those things are at least $20.

Sweet I have a creative vision.


Nubie, sorry I didn't look at the link you showed me but it was a zip file. As I was looking at it from work it wouldn't let me download it. Denied :( I'll check it out later. Hope your feeling better today :)
 
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fheusel posted on Jul 27 2006 at 01:53 AM said:
selling my gp2x to buy a new one is not an option - much too expensive

I have sold 2 and I lost some money on them, but it was only ~$20-$30, and if you buy play-asia it will be cheaper.

It all depends on what you want to do, I can guarentee you that it will cost at least 20-30 dollars to get an external DC-DC convertor chip working as elegantly as this mod.

Of course a quick hack is much cheaper, just use an external Radio Shack 4 AAA battery holder (~$2) with NiMH batteries in it, mine tops at 5.28 volts no-load on fully charged NiMH AAA 1,000mAh batteries (Wal-Mart, around $10).

You can do the entire mod, but put a connector for 5 volts in the design that is accessible externally, then plug in the battery pack when you need to, it will handle WiFi and 2.5" HDD likely in that manner.

Any damage caused by following this is not my fault, I only tested it with about 3 flash drive sticks at one time, it worked fine for that on an unpowered USB 1.1 mini-hub.
 
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Video Ipods can use video and audio on the same port without messing up headphones because they don't use the "standard" AV cable connection (which sounds like it isnt actually standard?). Anyways, check out this guide, which is for making your own video ipod AV cable from a "standard" av cable. Or if you get a video ipod cable, you could just figure out which connector video SHOULD be and try hooking that up to video (it wont be the yellow one, I can tell you that). Anyways, I hope this guide helps you to figure out how to wire this puppy up - this would be a great mod!

http://videoipodder.com/?p=22
 
I have the same kind of RCA cable that came with my camcorder and does fit into the headphone socket of my GP2x. In order to get video I would have to mod my 2x right? I'm just curious to see if audio would work via tv with the cables plugged in. Would it damage my 2x at all? Thanks-minkster
 
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